Drive-control apparatus for electric drive vehicle

ABSTRACT

A drive-control apparatus for an electric-drive vehicle drives and controls a vehicle driven by electric power generated from mechanical power produced by an internal combustion engine ( 1 ). In order to cool down an electric power converter ( 3 ) without increasing the engine-rotation speed during deceleration of the locomotive using electric braking; the drive-control apparatus includes a braking resistor ( 10 ) for dissipating electric power that is generated by a main rotating machine ( 4 ) and supplied through the electric power converter ( 3 ); a fan motor ( 7 ), whose pole number is changeable, supplied with alternating electric power that is generated by an auxiliary generator ( 6 ) and has a frequency proportional to a rotation speed of the internal combustion engine ( 1 ); a fan ( 8 ) for making an air flow in order to cool down the electric power converter ( 3 ), being driven by the fan motor ( 7 ); a pole-number-changing switch ( 9 ) for changing the pole number of the fan motor ( 7 ); and a controlling unit for controlling the internal combustion engine ( 1 ), the electric power converter ( 3 ), the braking resistor ( 10 ), and the pole-number-changing switch ( 9 ).

TECHNICAL FIELD

The present invention relates to drive-control apparatus that drive andcontrol a vehicle which is driven by electric power generated frommechanical power produced by an internal combustion engine.

BACKGROUND ART

In a conventional diesel-electric locomotive, a main generator directlycoupled to a diesel engine generates electric power and supplies theelectric power to a traction motor via an electric power converter. Thediesel engine and the main generator generate heat; therefore, they arecooled down by an engine fan mechanically direct-coupled to the engine.Furthermore, the traction motor and the electric power converter alsogenerate heat; therefore, they are cooled down by either the engine fanor an electric fan mechanically direct-coupled to an auxiliarygenerator.

The engine fan rotates at the same rotation speed as the engine;therefore, the air flow volume is approximately proportional to theengine rotation speed. In addition, an AC generator, which excels atmaintenance, is generally used as the auxiliary generator, and theoutput frequency thereof is proportional to the engine rotation speed.An induction motor, which excels at maintenance, is generally used asthe electric fan, and the rotation speed thereof is approximatelyproportional to the frequency of its power supply, so that the air flowvolume is approximately proportional to the engine rotation speed.

When the locomotive accelerates, the traction motor is supplied withoutput power from the diesel engine, through the main generator and theelectric power converter; therefore, the quantity of heat generated byeach of those devices is proportional to output power from the dieselengine. For this reason, the rotation speed of the diesel engine is madeapproximately proportional to its output power, so that the air flowvolumes made by the engine fan and the electric fan are approximatelyproportional to the rotation speed of the diesel engine. Operating thediesel engine with its rotation speed being approximately proportionalto its output power results in high fuel efficiency, thereby leading toa system configuration that gives high efficiency during accelerations.

On the other hand, when the locomotive decelerates, the traction motorand the electric power converter convert into electric power kineticenergy of the locomotive and its cars, so that a braking resistordissipates this electric power. During this period, the engine produceslittle mechanical power but the traction motor and the electric powerconverter generate heat; therefore, it is necessary to cool them down bythe engine fan or the electric fan. Each of the fans rotatesapproximately proportionally to the engine rotation speed and the airflow volume thereby is proportional to its rotation speed; therefore, inorder to adequately cool them down, it is necessary to rotate the engineat a higher speed.

When the diesel-electric locomotive runs into a tunnel and such,efficiency of cooling thereof is worsened; therefore, the speed of thetrain has been controlled in such a way that the quantity of the heatgenerated is within a range of its cooling capability.

Patent Document 1: Japanese Patent Laid-Open No.2000-203420

DISCLOSURE OF INVENTION

In the conventional diesel-electric locomotive employing electricbraking in order to cool down, using fans, the traction motor and theelectric power converter during the locomotive's deceleration, whileoutputting little power, the engine necessarily rotates at a high speed.This has led to low fuel efficiency during deceleration.

When the locomotive runs through sections, such as tunnels, where thecooling efficiency thereof is deteriorated, the locomotive has been runat a limited speed.

A drive-control apparatus for an electric-drive vehicle, according tothe present invention, drives and controls a vehicle which is driven byelectric power generated from mechanical power produced by an internalcombustion engine.

The drive-control apparatus includes an internal combustion engine forproducing mechanical power; a main generator and an auxiliary generatoreach for generating electricity, being supplied with the mechanicalpower that the internal combustion engine generates; a main rotatingmachine for producing mechanical power so as to drive the vehicle, beingsupplied with electric power that the main generator generates, and forgenerating electric power during the vehicle's deceleration; an electricpower converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith, and for receiving electric power generated by themain rotating machine; a braking resistor for dissipating electric powerthat is generated by the main rotating machine and supplied through theelectric power converter; a fan motor supplied with alternating electricpower that is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; and a controlling unit for controlling the internalcombustion engine, the electric power converter, the braking resistor,and the pole-number-changing switch.

Furthermore, a drive control apparatus for an electric-drive vehicledrives and controls a vehicle which is driven by electric powergenerated from mechanical power produced by an internal combustionengine. The drive-control apparatus includes an internal combustionengine for producing mechanical power; a main generator and an auxiliarygenerator each for generating electricity, being supplied with themechanical power that the internal combustion engine generates; a mainrotating machine for producing mechanical power so as to drive thevehicle, being supplied with electric power that the main generatorgenerates; an electric power converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith; a fan motor supplied with alternating electric powerthat is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; a controlling unit for controlling the internalcombustion engine, the electric power converter, and thepole-number-changing switch; and a position determination unit forlocating the position of the vehicle and inputting the position into thecontrolling unit; wherein the pole-number-changing switch is controlledso as to change the pole number to a small number when the positionobtained by the position determination unit indicates that the vehicleis in a tunnel.

Furthermore, a drive-control apparatus for an electric-drive vehicledrives and controls a vehicle which is driven by electric powergenerated from mechanical power produced by an internal combustionengine. The drive-control apparatus includes an internal combustionengine for producing mechanical power; a main generator and an auxiliarygenerator each for generating electricity, being supplied with themechanical power that the internal combustion engine generates; a mainrotating machine for producing mechanical power so as to drive thevehicle, being supplied with electric power that the main generatorgenerates; an electric power converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith; a fan motor supplied with alternating electric powerthat is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; a controlling unit for controlling the internalcombustion engine, the electric power converter, and thepole-number-changing switch; and a thermometer for measuring atemperature of the electric power converter so as to input thetemperature value into the controlling unit, wherein thepole-number-changing switch is controlled so as to change the polenumber to a small number when the temperature value measured by thethermometer is a predetermined value or higher.

A drive-control apparatus for an electric-drive vehicle, according tothe present invention, drives and controls a vehicle which is driven byelectric power generated from mechanical power produced by an internalcombustion engine.

The drive-control apparatus includes an internal combustion engine forproducing mechanical power; a main generator and an auxiliary generatoreach for generating electricity, being supplied with the mechanicalpower that the internal combustion engine generates; a main rotatingmachine for producing mechanical power so as to drive the vehicle, beingsupplied with electric power that the main generator generates, and forgenerating electric power during the vehicle's deceleration; an electricpower converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith, and for receiving electric power generated by themain rotating machine; a braking resistor for dissipating electric powerthat is generated by the main rotating machine and supplied through theelectric power converter; a fan motor supplied with alternating electricpower that is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; and a controlling unit for controlling the internalcombustion engine, the electric power converter, the braking resistor,and the pole-number-changing switch. Therefore, when theelectric-power-driven vehicle using its electric braking decelerates,the apparatus can cool down the electric power converter and the fanmotor without keeping a high rotation speed of the engine, bringing highfuel efficiency of the engine.

Furthermore, a drive control apparatus for an electric-drive vehicledrives and controls a vehicle which is driven by electric powergenerated from mechanical power produced by an internal combustionengine. The drive-control apparatus includes an internal combustionengine for producing mechanical power; a main generator and an auxiliarygenerator each for generating electricity, being supplied with themechanical power that the internal combustion engine generates; a mainrotating machine for producing mechanical power so as to drive thevehicle, being supplied with electric power that the main generatorgenerates; an electric power converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith; a fan motor supplied with alternating electric powerthat is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; a controlling unit for controlling the internalcombustion engine, the electric power converter, and thepole-number-changing switch; and a position determination unit forlocating the position of the vehicle and inputting the position into thecontrolling unit; wherein the pole-number-changing switch is controlledso as to change the pole number to a small number when the positionobtained by the position determination unit indicates that the vehicleis in a tunnel, which brings an effect in that the electric-drivevehicle does not need to slow down for cooling while in tunnels.

Furthermore, a drive control apparatus for an electric-drive vehicledrives and controls a vehicle which is driven by electric powergenerated from mechanical power produced by an internal combustionengine. The drive-control apparatus includes an internal combustionengine for producing mechanical power; a main generator and an auxiliarygenerator each for generating electricity, being supplied with themechanical power that the internal combustion engine generates; a mainrotating machine for producing mechanical power so as to drive thevehicle, being supplied with electric power that the main generatorgenerates; an electric power converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith; a fan motor supplied with alternating electric powerthat is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; a controlling unit for controlling the internalcombustion engine, the electric power converter, and thepole-number-changing switch; and a thermometer for measuring atemperature of the electric power converter so as to input thetemperature value into the controlling unit, wherein thepole-number-changing switch is controlled so as to change the polenumber to a small number when the temperature measured by thethermometer is a predetermined value or higher, which brings an effectin that the electric-drive vehicle does not need to slow down forcooling while in tunnels.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram when a drive-control apparatus, according toEmbodiment 1 of the present invention, for an electric-drive vehicle isapplied to a diesel-electric locomotive;

FIG. 2 is a block diagram when a drive-control apparatus, according toEmbodiment 2 of the present invention, for the electric-drive vehicle isapplied to the diesel-electric locomotive; and

FIG. 3 is a block diagram when a drive-control apparatus, according toEmbodiment 3 of the present invention, for the electric-drive vehicle isapplied to the diesel-electric locomotive.

REFERENCE NUMERALS

-   1 diesel engine (internal combustion engine)-   2 main generator-   3 electric power converter-   4 traction motor (main rotating machine)-   5 fan-   6 auxiliary generator-   7 induction motor whose pole number is changeable (fan motor)-   8 fan-   9 pole-number-changing switch-   10 braking resistor-   11 11A 11B controller (controlling unit)-   12 GPS device (position determination unit)-   13 thermometer

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

FIG. 1 is a block diagram when a drive-control apparatus, according toEmbodiment 1 of the present invention, for an electric-drive vehicle isapplied to a diesel-electric locomotive. In the figure, double linesrepresent mechanical couplings; bold lines, electrical connections;directional lines, signal flows. In addition, air flows are representedby wavy lines having arrows.

AC power is generated by a main generator 2 mechanically coupleddirectly to a diesel engine 1, an internal combustion engine. Thegenerated electric power is supplied via an electric power converter 3to a traction motor 4, a main rotating machine. Being supplied with theelectric power, the traction motor 4 produces force for driving thevehicle. On the other hand, when the vehicle decelerates, the motorgenerates electricity to generate braking force. The electric powerconverter 3 receives the electric power that the traction motor 4generates. The electric power is thus fed bidirectionally between theelectric power converter 3 and the traction motor 4.

A fan 5 is mechanically coupled directly to the engine 1 in order tocool down the engine 1 and the main generator 2. An auxiliary generator6 is also mechanically coupled directly with the engine 1 in order togenerate AC power with a frequency proportional to the engine rotationspeed.

The electric power generated by the auxiliary generator 6 is fed into aninduction motor 7—a fan motor whose pole number is changeable, forexample, between four and eight. Changing the pole number is performedby changing the primary winding connection of the induction motor 7between the delta connection and the star connection. Changing the polenumber may be performed by PAM (pole amplitude modulation) method.

A fan 8 is directly coupled to the rotation shaft of the induction motor7, so that the electric power converter 3 and the traction motor 4 arecooled down with the air flow made by the fan 8. The air flow volumemade by the fan 8 is proportional to the rotation speed of the engine 1.

Assuming that the frequency of the AC power inputted into the inductionmotor 7 is f (Hz), the pole number of the induction motor 7, PP, therotation speed of the induction motor 7, N (revolutions/second), and theslip frequency thereof is ignored, an equation is obtained below.N=2* (f/PP)  (1)

Equation (1) shows that when the pole number PP is large for the samefrequency f, the rotation speed N is small. A pole-number-changingswitch 9 changes the pole number of the induction motor 7 to a low-speedstate (eight poles) or a high-speed state (four poles). Here, under thesame frequency of the AC power, “high-speed” and “low-speed” mean thatthe rotation speed of the induction motor 7 is high and that the speedis low, respectively. The pole number pair of the induction motor 7 maybe two and four, six and eight and such, as long as the pole number ischanged between different ones. The ratio between the pole numbers to bechanged is appropriately determined in accordance with the purpose ofuse.

When the locomotive decelerates, a braking resistor 10 dissipates theelectric power that the traction motor 4 generates from the kineticenergy of the locomotive and its cars. The braking resistor 10 is cooleddown by the air flow generated while running. The drive-controlapparatus is configured in a manner that the heat generated by thebraking resistor 10 has little effect to the temperatures of theelectric power converter 3 and the traction motor 4. The reason forusing the braking resistor is to maintain the fuel efficiency, theacceleration performance and such of the locomotive while using electricbraking. On the other hand, if a battery and such is used to store theelectric power generated by electrically braking, the battery that has anecessary capacity for the braking is heavy, so that the total weight ofthe locomotive increases. If the total weight of the locomotive isincreased, its fuel efficiency and the acceleration performance becomesdeteriorated while running.

A controller 11—a controlling unit—controls the engine 1, the electricpower converter 3, the pole-number-changing switch 9, and the brakingresistor 10. Not shown in the figure, a control signal from the cab isinputted into the controller 11.

The operations will be explained. When the locomotive accelerates, theengine 1 is controlled to rotate at a predetermined rotation speed f1,so that the main generator 2 and the auxiliary generator 6 generateelectricity. The electric power generated by the main generator 2 isconverted by the electric power converter 3 into electric power having apredetermined frequency and voltage; the traction motor 4 is suppliedwith the converted electric power to produce a predetermined torque. Thepole-number-changing switch 9 is in the low-speed state (eight poles),so that the induction motor 7 and the fan 8 rotate at a rotation speedN1(=f1/4), whereby all of the engine 1, the main generator 2, theelectric power converter 3 and the traction motor 4 operate efficiently,and necessary cooling is performed.

When the locomotive decelerates, the engine 1 rotates at a rotationspeed f2A that is determined as described later. The main generator 2does not generate electricity and the auxiliary generator 6 generatesthe electric power consumed by the induction motor 7 and such. Theelectric power converter 3 outputs an AC voltage having such a frequencythat makes the traction motor 4 generate electricity; the electric powergenerated by the traction motor 4 is delivered to the braking resistor10 through the electric power converter 3, and then dissipated by thebraking resistor 10. The pole-number-changing switch 9 is in thehigh-speed state (four poles), so that the induction motor 7 and the fan8 rotate at a rotation speed N2(=f2A/2). At the rotation speed N2, thefan 8 can make an air flow that can sufficiently cool down the electricpower converter 3 and the traction motor 4. When thepole-number-changing switch 9 is in the low-speed state (eight poles),given that an engine rotation speed that makes the induction motor 7 andthe fan 8 rotate at the rotation speed N2 is expressed as a symbol f2B,a relationship between f2A and f2B is given as follows:f2A=2*N2=f2B/2  (2).

Equation (2) means that during deceleration periods the rotation speedof the engine 1 can be halved, comparing with that in the low-speedstate (eight poles), by turning the pole-number-changing switch 9 to thehigh-speed state (four poles).

As described above, when the locomotive using electric brakingdecelerates, the drive-control apparatus for electric-drive vehiclesaccording to the present invention can cool down the electric powerconverter and the traction motor without keeping a high rotation speedof the engine by using the pole-number-changing switch and the inductionmotor whose pole number is changeable, which brings an effect that thefuel efficiency of the engine is improved. An induction motor whose polenumber is changeable is a little more expensive than a conventional one;however, the apparatus requires no other expensive components, so thatthe fuel efficiency during deceleration periods can be enhanced at lowcosts.

Control operations during transition to deceleration are performed inthe following order.

-   Step 1: Decreasing the rotation speed of the engine 1 to the    predetermined rotation speed f2A.-   Step 2: Controlling the electric power converter 3 in such a way    that the electric power converter outputs an AC voltage to make the    traction motor 4 generate electricity.-   Step 3: Putting the braking resistor 10 into a state in which the    braking resistor dissipates the electric power from the electric    power converter 3.-   Step 4: Turning the pole-number-changing switch 9 to the high-speed    state (four poles).

Timing restrictions on the control operations for deceleration will beexplained below. Step 3 is performed simultaneously with Step 2 orwithin a predetermined time difference therebetween. In a state A whereStep 2 has been performed but Step 3 is not performed, the electricpower generated by the traction motor 4 is not dissipated, so that it isstored in a smoothing condenser provided in the electric power converter3. To prevent overvoltage across the smoothing condenser, the period ofthe state A is controlled to be within a predetermined time. In a stateB where Step 2 is not performed and Step 3 has been performed, thebraking resistor 10 wastes the electric power generated by the generator2.

The state B is also undesirable; thus, Step 3 is controlled not toprecede Step 2 by a period exceeding a predetermined one. In addition,the state B is less urgent than the state A; therefore, thepredetermined period by which Step 3 precedes may be set longer than thepredetermined period by which the Step 3 lags.

The induction motor 7 has an upper limit of the rotation speed; when therotation speed exceeds the upper limit—which state is called as a stateC—by turning, without decreasing the rotation speed of the engine 1, thepole-number-changing switch 9 to the high-speed state (four poles), Step4 needs to be performed after Step 1. Otherwise, Step 4 may be performedbefore or after any step.

Control operations during transition from deceleration are performed inthe following order.

-   Step 5: Turning the pole-number-changing switch 9 to the low-speed    state (eight poles).-   Step 6: Putting the braking resistor 10 into a state in which the    braking resistor does not dissipate electric power.-   Step 7: Controlling the electric power converter 3 in such a way    that the electric power converter outputs an AC voltage to make the    traction motor 4 operate as a motor.-   Step 8: Increasing the rotation speed of the engine 1 to the    predetermined rotation speed f1.

The timing restrictions on the control operations are similar to thoseduring transition to deceleration. A state in which Step 6 has beenperformed but Step 7 is not performed is the same as the state A; Astate in which Step 7 has been performed but Step 6 is not performed isthe same as the state B. Step 7 is performed simultaneously with Step 8or within a predetermined time difference therebetween. Step 5 and Step8 are performed also in an order so as not to fall into the state C.

In this embodiment, although one controller 11 controls the engine 1,the electric power converter 3, and the braking resistor 10, its controloperations may be assigned to a plurality of controllers. In that case,the controlling unit includes the plurality of controllers. The fan 8cools down both the electric power converter 3 and the traction motor 4.However the fan may cool down only the electric converter 3. In thatcase, the traction motor 4 is cooled down by cooling with liquid,cooling with air flow made by its own rotation, or the like.

In the explanation above, a diesel engine is exemplified as an internalcombustion engine; however, other types of internal combustion enginessuch as gasoline engines may be used. Having been explained thedrive-control apparatus used for a locomotive, the drive-controlapparatus can be applied to automobiles, construction machines, and thelike. The drive-control apparatus may be applicable to any type ofelectric-drive vehicles which are driven by electric power generatedfrom mechanical power produced by an internal combustion engine.

That is also true of embodiments described below.

Embodiment 2

In Embodiment 2, the pole number of a motor rotating a fan can bechanged so that a locomotive does not need to decelerate for coolingwhile running through a tunnel and such. When the locomotive runsthrough a tunnel, the temperature of the air in the tunnel rises due toexhaust gas produced by the engine, so that the temperature of the airsent by the fan rises, which lowers its cooling performance. Therefore,a locomotive has conventionally been run at a limited speed whilerunning through a tunnel, in order to control the quantity of thegenerated heat within a range of its cooling capability.

FIG. 2 is a block diagram when a drive-control apparatus for anelectric-drive vehicle, according to Embodiment 2 of the presentinvention, is applied to a diesel-electric locomotive. Differences fromFIG. 1 of Embodiment 1 will only be explained below. A GPS (GlobalPositioning System) device 12 is added as a position determination unitthat determines the locomotive's location. The signal from the GPSdevise 12 is inputted to a controller 11A.

The operations will be explained below. When the location of thelocomotive, obtained from the GPS device 12, is in a place in which anormal cooling condition is applied, the engine 1 is controlled torotate at a predetermined rotation speed fl so as to produce a necessarytorque, so that the main generator 2 and the auxiliary generator 6generate electricity. The electric power generated by the main generator2 is converted by the electric power converter 3 into electric powerhaving a predetermined frequency and voltage, from which the tractionmotor 4 produces a predetermined torque. The pole-number-changing switch9 is in the low-speed state (eight poles), so that the induction motor 7and the fan 8 rotate at a rotation speed N1(=f1/4), whereby all of theengine 1, the main generator 2, the electric power converter 3 and thetraction motor 4 are efficiently operated, and necessary cooling isperformed.

While the locomotive is running through sections, such as tunnels, inwhich its cooling efficiency is deteriorated, the controller 11A turnsthe pole-number-changing switch 9 to the high-speed state (four poles).Here, the rotation speed and such of the engine 1 is appropriatelycontrolled, depending on curves and slopes of railway tracks andpositional relations with respect to stations where the locomotivestops. That holds true when the locomotive runs through sections otherthan tunnels.

The rotation speeds of the induction motor 7 and the fan 8 double, thatis, to become 2*N1 (=f1/2), which doubles the air flow volume. Thecooling efficiency in tunnels seldom becomes lower than 50 percent ofits normal efficiency; therefore, its cooling performance is assured intunnels by doubling the volume of air. This brings effects in that thelocomotive does not need to decelerate for cooling in tunnels, and thatthe locomotive does not waste fuel due to excess cooling while runningthough sections outside tunnels.

If the pole-number-changing switch 9 is kept at the high-speed state(four poles), an appropriate air flow volume is obtained while runningthrough tunnels. However, while running through sections outsidetunnels, the fan generates excessive volume of air flow. It is to beavoided to excessively send air—resulting in wasting fuel.

Instead of the GPS device, the position determination unit may be adevice that determines the locomotive's location by communicatinginformation with devices on the ground.

When electric braking is not used, the braking resistor may not beprovided.

That is also true of embodiments described below.

Embodiment 3

In Embodiment 3, a case is described, in which a thermometer to measurethe temperature of the electric power converter is provided, and thedrive-control apparatus turns the pole-number-changing switch to thehigh-speed state in order to increase its cooling performance when thetemperature of the electric power converter exceeds a predeterminedvalue. p FIG. 3 is a block diagram when a drive-control apparatus for anelectric-drive vehicle, according to Embodiment 3 of the presentinvention, is applied to a diesel-electric locomotive. Differences fromFIG. 2 of Embodiment 2 will only be explained below. Instead of the GPSdevice 12, a thermometer 13 is provided to measure the temperature ofthe electric power converter 3. The temperature value measured by thethermometer 13 is inputted into a controller 11B.

The operations will be explained below. When the temperature value ofthe electric power converter 3 measured by the thermometer 13 is apredetermined value or lower, the operations are similar to those ofEmbodiment 2 while the locomotive is running through sections outsidetunnels.

When the temperature value measured by the thermometer 13 exceeds thepredetermined value, the controller 11B turns the pole-number-changingswitch 9 to the high-speed state (four poles). Thus, the rotation speedsof the induction motor 7 and the fan 8 double, that is, to become 2*N1(=f1/2), which doubles the air flow volume. Because the air flowvolume—its cooling performance—doubles, the electric power converter 3and the traction motor 4 can be sufficiently cooled down. When thetemperature of the electric power converter 3 falls down and thetemperature value measured by the thermometer 13 becomes thepredetermined value or lower, the controller 11B turns thepole-number-changing switch 9 to the low-speed state (eight poles).

Even when the locomotive runs through sections such as tunnels in whichits cooling efficiency is deteriorated, the drive-control apparatusbrings effects in that the locomotive does not need to speed down forcooling, and that the locomotive does not waste fuel due to constantexcess cooling.

The configurations described in the above embodiments are examples ofaspects of the present invention. Combinations of the present inventionwith heretofore known techniques can be made, and various changes, suchas eliminating some of the components, can be made without departingfrom the scope of the invention.

1. A drive-control apparatus for an electric-drive vehicle, that drivesand controls a vehicle driven by electric power generated frommechanical power produced by an internal combustion engine, theapparatus including: an internal combustion engine for producingmechanical power; a main generator and an auxiliary generator each forgenerating electricity, being supplied with the mechanical power thatthe internal combustion engine generates; a main rotating machine forproducing mechanical power so as to drive the vehicle, being suppliedwith electric power that the main generator generates, and forgenerating electric power during deceleration of the vehicle; anelectric power converter for performing conversion of themain-generator-generated electric power to supply the main rotatingmachine therewith, and for receiving electric power generated by themain rotating machine; a braking resistor for dissipating electric powerthat is generated by the main rotating machine and supplied through theelectric power converter; a fan motor supplied with alternating electricpower that is generated by the auxiliary generator and has a frequencyproportional to a rotation speed of the internal combustion engine, thefan motor whose pole number is changeable; a fan for making an air flowin order to cool down the electric power converter, being driven by thefan motor; a pole-number-changing switch for changing the pole number ofthe fan motor; and a controlling unit for controlling the internalcombustion engine, the electric power converter, the braking resistor,and the pole-number-changing switch.
 2. A drive-control apparatus for anelectric-drive vehicle according to claim 1, wherein thepole-number-changing switch is controlled so as to change the polenumber to a smaller number when the main rotating machine is generatingelectricity.
 3. A drive-control apparatus for an electric-drive vehicle,that drives and controls a vehicle driven by electric power generatedfrom mechanical power produced by an internal combustion engine, theapparatus including: an internal combustion engine for producingmechanical power; a main generator and an auxiliary generator each forgenerating electricity, being supplied with the mechanical power thatthe internal combustion engine generates; a main rotating machine forproducing mechanical power so as to drive the vehicle, being suppliedwith electric power that the main generator generates; an electric powerconverter for performing conversion of the main-generator-generatedelectric power to supply the main rotating machine therewith; a fanmotor supplied with alternating electric power that is generated by theauxiliary generator and has a frequency proportional to a rotation speedof the internal combustion engine, the fan motor whose pole number ischangeable; a fan for making an air flow in order to cool down theelectric power converter, being driven by the fan motor; apole-number-changing switch for changing the pole number of the fanmotor; a controlling unit for controlling the internal combustionengine, the electric power converter, and the pole-number-changingswitch; and a position determination unit for locating the position ofthe vehicle and inputting the position into the controlling unit;wherein the pole-number-changing switch is controlled so as to changethe pole number to a smaller number when the position obtained by theposition determination unit indicates that the vehicle is in a tunnel.4. A drive-control apparatus for an electric-drive vehicle, that drivesand controls a vehicle driven by electric power generated frommechanical power produced by an internal combustion engine, theapparatus including: an internal combustion engine for producingmechanical power; a main generator and an auxiliary generator each forgenerating electricity, being supplied with the mechanical power thatthe internal combustion engine generates; a main rotating machine forproducing mechanical power so as to drive the vehicle, being suppliedwith electric power that the main generator generates; an electric powerconverter for performing conversion of the main-generator-generatedelectric power to supply the main rotating machine therewith; a fanmotor supplied with alternating electric power that is generated by theauxiliary generator and has a frequency proportional to a rotation speedof the internal combustion engine, the fan motor whose pole number ischangeable; a fan for making an air flow in order to cool down theelectric power converter, being driven by the fan motor; apole-number-changing switch for changing the pole number of the fanmotor; a controlling unit for controlling the internal combustionengine, the electric power converter, and the pole-number-changingswitch; and a thermometer for measuring a temperature of the electricpower converter so as to input the temperature value into thecontrolling unit, wherein the pole-number-changing switch is controlledso as to change the pole number to a smaller number when the temperaturevalue measured by the thermometer is a predetermined value or higher.